Independent External Validation of the METSSS Model Predicting Survival After Palliative Radiotherapy

Anticancer Res. 2022 Mar;42(3):1477-1480. doi: 10.21873/anticanres.15618.

Abstract

Background/aim: A validation of the recently published METSSS model (developed from a large US database) predicting survival after palliative radiotherapy was performed. METSSS includes age, sex, cancer type, localization of distant metastases, comorbidity, and radiotherapy site.

Patients and methods: Both 1- and 5-year survival was assessed in the validation cohort. Deviations between model-predicted and observed survival were analyzed.

Results: The METSSS model predicted a 1-year survival of 29% (cohort median, predicted probability 0-74% in individual patients). The observed 1-year survival rate was 33% (median survival 5.3 months). The corresponding figures for predicted 5-year survival were 0% and 0-46% (observed rate 3%). Statistical comparison of the survival curves was possible for two of three strata (insufficient number of low-risk patients) and the resulting p-value was 0.045.

Conclusion: A complete validation was hampered by imbalances in group size. More than 90% of our patients were classified as high risk. If this distribution is representative for other countries, the METSSS model might need adjustment. However, its general ability to predict survival appears promising.

Keywords: Palliative radiation therapy; bone metastases; brain metastases; comorbidity; prognostic model; radiotherapy.

Publication types

  • Validation Study

MeSH terms

  • Databases, Factual
  • Decision Support Techniques*
  • Dose Fractionation, Radiation
  • Female
  • Humans
  • Male
  • Neoplasms / mortality
  • Neoplasms / pathology
  • Neoplasms / radiotherapy*
  • Palliative Care*
  • Predictive Value of Tests
  • Radiation Dosage
  • Reproducibility of Results
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Treatment Outcome